#include "interface.h"
#include <math.h>

// Constructor must call the base class constructor.
Viewer::Viewer(QWidget *parent)
	: QGLGraphicsViewer(parent)
{
  restoreStateFromFile();
  help();
}

void Viewer::draw()
{
  // Draws a spiral
  const float nbSteps = 200.0;
  glBegin(GL_QUAD_STRIP);
  for (float i=0; i<nbSteps; ++i)
	{
	  float ratio = i/nbSteps;
	  float angle = 21.0*ratio;
	  float c = cos(angle);
	  float s = sin(angle);
	  float r1 = 1.0 - 0.8*ratio;
	  float r2 = 0.8 - 0.8*ratio;
	  float alt = ratio - 0.5;
	  const float nor = .5;
	  const float up = sqrt(1.0-nor*nor);
	  glColor3f(1.0-ratio, 0.2f , ratio);
	  glNormal3f(nor*c, up, nor*s);
	  glVertex3f(r1*c, alt, r1*s);
	  glVertex3f(r2*c, alt+0.05, r2*s);
	}
  glEnd();
}

QString Viewer::helpString() const
{
  QString text("<h2>I n t e r f a c e</h2>");
  text += "A GUI can be added to a QGLGraphicsViewer widget using Qt's <i>Designer</i>. Signals and slots ";
  text += "can then be connected to and from the viewer.<br><br>";
  text += "You can install the QGLGraphicsViewer designer plugin to make the QGLGraphicsViewer appear as a ";
  text += "standard Qt widget in the Designer's widget tabs. See installation pages for details.";
  return text;
}
